Buki Rinkevich National institute of Oceanography Haifa, Israel

Transcription

1 Buki Rinkevich National institute of Oceanography Haifa, Israel

2 Is there a hope for natural rehabilitation processes in degrading coral reefs? The pessimistic view

3 Rapid climatic change has already caused changes to the distributions of many plants and animals, leading to severe range contractions and the extinction of some species The geographic ranges of many species are moving toward higher altitudes in response to shifts in the habitats to which these species have adapted. It already appears that some species are unable to disperse or adapt fast enough to keep up with the high rates of climate change. These organisms face increased extinction risk, and, as a result, whole ecosystems, such as cloud forests and coral reefs, may cease to function in their current form.. Therefore, resource managers and policy-makers must contemplate moving species to sites where they do not currently occur or have not been known to occur in recent history.

4 The statements.. Coral reefs suffer worldwide decline/degradation This poor state of the reefs is due to (a) global changes and (b) anthropogenic activities This decline has raised the need for the development of adequate rehabilitation methodologies Efforts to conserve degrading reefs have failed, in most of the cases, to produce significant results There is a need for active restoration measures The most effective approach is the concept of gardening reef areas

5 Active vs. passive approaches Tsunami impacts in Thailand Placing corals into right position if possible! Repairing sea fan Silviculture

6 The Gardening Strategy A two steps restoration measure: Mariculture (in situ or ex situ) of coral colonies in protected nurseries (artificial substrates) Nursery grown coral colonies are transplanted to degraded reef areas

7 Step I : mid-water floating nursery

8 Attached to the bottom.. Strategies for nursery types Leg fixed

9 Step II : nutrient enriched area The location

10 7 months of in situ growth Fish Farm IUI

11 Hundreds of nubbins in the size of a single to few polyps each, can be produced from a single branching coral colony Under proper farming conditions, most of the nubbins survive and produce new coral colonies Step III : source material- nubbins

12 Coral fragments, even partially dead, may be used as an excellent source for nubbins The use of corals of opportunity

13 An untrained person produces 100 nubbins/h

14 Nubbins Development of monocultures Reduced genetic heterogeneity No negative ecological impacts High survivorship No impact on reproduction of donor colonies Unlimited source material Availability-year round High numbers of added colonies per genotype Lower growth rates Longer mariculture periods Ex situ work

15 Step IV : large quantities, thousands

16 About 7000 nubbins and branches from 4 coral genera were farmed in a nursery (6 m depth), about 10 m from the fish cages here is the start.

17 Fast growth of an Acropora branch within 400 days of nursery time

18 Favia favus Growth of 160%in size within 9 nursery months

19 After 2 years in the nursery: large colonies of 20 cm in diameter have developed from the nubbins

20 Mid-water coral nurseries a source for new coral colonies Tens of thousands of nubbins and branches from > 85 coral species were already farmed in various nursery types, worldwide (the Philippines, Singapore, Thailand, Eilat- the Red Sea, Tanzania- Zanzibar & Mafia Islands, Seychelles, Mauritius, Colombia, Jamaica)

21 Frame nursery Mini, depth adjustable nursery Step V: different nursery types, different needs Pipe nursery Rope nursery

22 Rope nursery

23 One year results Acropora hemprichi Pocillopora verrucosa

24 M. digitata P. frondifera Thailand nursery

25 Vertical rope nursery- Eilat, May 2008

26 Depth adjustable nursery in Jamaica

27 The nursery- oasis in blue waters Step VI : floating artificial reefs

28 Hundreds of invertebrates that settle, develope, and reproduce in the nursery

29 Step VII : nursery maintenance

30 Drupella cornus

31 Corals grow faster in an enriched nutrient environment, but fouling organisms too, some of them may harm the corals.

32 Step VIII : nurseries as larval dispersion hubs Tens of millions of larvae/ nursery/reproductive season

33 Maintenance with the aid of grazers Principles for nursery : A protected area from divers, storms Away from the reef Preferably in a nutrient enriched area The use of nubbins and small branches to produce huge numbers of coral colonies Mid water nursery Multi-deck nursery Various type of nurseries

34 Step IX : new transplantation methodologies

35 Even there is no phase shift, reefs of today are not reefs of yesterday.or tomorrow- Eilat as a study case * * * *

36 How to transplant? D2 D2 D3 E. lamellosa D1 = 6cm D2 = 13 cm D3 = 50-40cm D1 D3 D1 M. digitata D1 = 15cm D2 = 10cm D3 = 50-40cm P. damicornis D1 = 7.5cm D2 = 10cm D3 = 50-40cm PATCH vs. ORDERED TRANSPLANTATIONS MONO- vs. MULTI (mixed vs. uniform) GENOTYPES

37 Thailand- transplantation on metal mesh with cable ties On rubbles, soft bottoms

38 Bolinao, soft substrate -1y After

39 5000 colonies in 1d by a team of 6 people Bolinao Rope nursery translocation Corals transplantation

40 Rope nursery- Bolinao Transplantation 10 months later

41 Blending rope transplantation into the reef

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43 Transplantation processes: 3 sets of repeated transplantations Number of colonies Coral species Transplanted on Distances between colonies Transplantation 1 (November 2005) 554 Stylophora pistillata Pocillopora damicornis 5 knolls 20 cm Transplantation 2 (May 2007) 316 Stylophora pistillata Pocillopora damicornis Acropora sp. Millepora dichotoma 2 of previously transplanted knolls 10 cm Transplantation 3 (September 2008) 530 Stylophora pistillata Pocillopora damicornis Acropora sp. Millepora dichotoma 2 of previously transplanted knolls and 1 new knoll 10 cm

44 Long term survivor of transplants: all species (%) T1: Survivorship of 554 farmed transplants and 76 natal controls over 6 ys 20 0 Transplants Natal controls Months after transplantation T2: Survivorship of 306 farmed transplants and 103 natal controls over 4.5 ys (%) Transplants Natal controls Months after transplantation

45 Single vs. repeated transplantation scheme: Improved survival following repeated transplantations Transplants survival over 3.2 ys Survival (%) Colonies added to previously transplanted plots Colonies from a single transplantation act Months after transplantation

46 July 201 1, 5 years following the restoration of denuded knolls in Dekel Beach, Eilat

47 Transplants: contribution to larval pool Improved reproductive capacity compared to natal colonies maintained over time Average number of planulae / colony collected from natal and transplanted S. pistillata Average planulae / colony Natal colonies b a T1 T2 b a b b b b Natal colonies T1 T2 T3 b b b a Natal colonies T1 T2 T3 b b b a Natal colonies T1 T2 T3 b b a Natal colonies T1 T2 T3 ±SE; Mann- Whitney P<0.05 after Bonferroni correction 0-2 vs

48 nursery Transplanted colonies Restoration operation dates and major weather events 1, monitoring dates for nursery; 2, monitoring dates for transplanted colonies. Step X : Reef restoration and global changes

49 The gardening concept has faced four major obstructions, all are satisfactorily deciphered: Developing the needed credentials for farming a wide variety of coral species in mid-water nurseries The ability to develop stocks of coral colonies; employing the nubbins methodology Documentation that nursery farmed coral colonies perform well in their new homes, following transplantation Verification of the low cost gardening approach (down to 0.17 and 0.19 US$/coral colony for farming and transplantation, phases, respectively Fifth challenge: Performing a large, ecologically profound restoration act (hundreds of thousands of coral colonies/site) to reveal the ecological engineering capacities of large-scale transplantation acts.

50 Restoration scenarios Primeval characters Boosting reef services (e.g., artificial reefs for fisheries) Reef services 6?? Replacement status Restored 3 5 5?? Restored 1 Restored 4?? Degraded reef Degraded status Low Replacement status Ecological complexity 7?? aiming to increase biodiversity (e.g., the concept of assisted colonization ) High

51 Thank you